A few days ago I asked you guys about some restaurants in NY, and now I think I also will have time to go to Boston. What are the recommendations to do there?
Also would like to know how feasible is to make a day trip from NY to Buffalo by plane to visit the Niagara Falls.
Would be better Chicago instead of Boston?
Suggestions are welcome!

I have never been to Chicago but as a Boston resident I can tell you this city is definitely worth visiting (besides, it is closer to NY and you can get here from there very cheaply, $15 by bus each way).

In Boston I would recommend as starters the Freedom Trail, walking around Back Bay and Beacon Hill and parts of the Waterfront. If you have some more time go visit Cambridge just across the river (Hah-vard and MIT) and if you're thinking of renting a car there are some nice ski resorts not too far away. I don't know what time of the year you are thinking of coming but if it is in the summer there are also some very nice coastal/beach towns nearby (Rockport is my current favorite, and accessible by commuter rail too).

You can take an entire day for it or be quick and do it in a few hours. The trail takes you to the USS Constitution which I recommend visiting, the adjacent museum is nice as well. End the day with a walk to Bunker Hill Monument and through the neighbourhood.

Quoting Pyrex (Reply 1):go visit Cambridge just across the river (Hah-vard and MIT)

I've only been to Hah-vid Yahd, it was well worth the visit.

As I like to get overviews of the cities I visit, I recommend the deck on top of the Prudential Center. It's a bit on the high end price-wise, as are all of these places, but to me well worth it. You can also go whale-watching (dress well even in the summer, you'll be on the North Atlantic Ocean for hours) which I found marvellous, and then of course, this being a.net, you can go spotting on Castle Island. If planes depart from the rioght runway(s), you'll be treated to quite a few sights. I met A.net member CastleIsland there, together with others and we had a great time... no airport terminal "Daddy, is that a 747?" "No, those are all Jumbo Jets!" talk within miles, for instance. ( Eeeggs! Come To Boston To Have Some, A.netters!(by Aloges May 22 2007 in Non Aviation) )